The structure of a phosphor powder is an important factor that affects the luminous efficiency of all kinds of electric light sources. The flat-plate shaped phosphor powder layer is a typical phosphor powder structure currently used in many electric light source devices, such as in an FED device, the phosphor powder is coated on the planar anode material to form a phosphor powder layer, and the phosphor powder layer emits light under the accelerated bombardment of the electron beam emitted from the cathode; another example is for the LED light source, packaging the LED light source with a flat-plate shaped phosphor powder layer is another important type. It has been reported that, compared to the flat-plate shaped phosphor powder layer, the non-planar phosphor powder layer with concavo-convex structure on the surface may improve the luminous efficiency of the FED device and LED device packaged thereby, because the area of the phosphor powder layer in unit area is increased.
Currently, however, the main preparation methods of phosphor powder layer are as follows: precipitation process, silk-screen printing process and spin coating method, and these processes can only be used to manufacture a flat-plate shaped phosphor powder layer on a flat surface, but it is difficult to obtain a non-planar phosphor powder layer with good consistency and uniformity by these processes. Accordingly, a preparation method of a non-planar phosphor powder layer is needed urgently.